When I too long have looked upon your face,
Wherein for me a brightness unobscured
Save by the mists of brightness has its place,
And terrible beauty not to be endured,
I turn away reluctant from your light,
And stand irresolute, a mind undone,
A silly, dazzled thing deprived of sight
From having looked too long upon the sun.
Then is my daily life a narrow room
In which a little while, uncertainly,
Surrounded by impenetrable gloom,
Among familiar things grown strange to me
Making my way, I pause, and feel, and hark,
Till I become accustomed to the dark.

Edna St. Vincent Millay

http://www.poemhunter.com/poem/sonnets-07-when-i-too-long-have-looked-upon-your/